How severe is CVE-2026-5263?

CVE-2026-5263 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-5263 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-5263?

CVE-2026-5263 affects Wolfssl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-5263?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-5263 have an EU (EUVD) identifier?

Yes. CVE-2026-5263 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21178.

When was CVE-2026-5263 published?

CVE-2026-5263 was published on 2026-04-09 and last updated on 2026-07-02.

CVE-2026-5263

CVE-2026-5263 is a medium-severity vulnerability in Wolfssl with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v4: 7.0
EPSS exploit prediction: 0% (6th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-21178
Weakness: CWE-295
Affected product: Wolfssl
Published: 2026-04-09
Last modified: 2026-07-02

Description

URI nameConstraints from constrained intermediate CAs are parsed but not enforced during certificate chain verification in wolfcrypt/src/asn.c. A compromised or malicious sub-CA could issue leaf certificates with URI SAN entries that violate the nameConstraints of the issuing CA, and wolfSSL would accept them as valid.

Frequently asked questions

What is CVE-2026-5263?: URI nameConstraints from constrained intermediate CAs are parsed but not enforced during certificate chain verification in wolfcrypt/src/asn.c. A compromised or malicious sub-CA could issue leaf certificates with URI SAN entries that violate the nameConstraints of the issuing CA, and wolfSSL would accept them as valid.
How severe is CVE-2026-5263?: CVE-2026-5263 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-5263 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-5263?: CVE-2026-5263 affects Wolfssl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-5263?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-5263 have an EU (EUVD) identifier?: Yes. CVE-2026-5263 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-21178.
When was CVE-2026-5263 published?: CVE-2026-5263 was published on 2026-04-09 and last updated on 2026-07-02.

References

Affected products (1)

cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*

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